Engine components (such as cylinders and valves) may be intermittently diagnosed for damage and degradation incurred during engine operation. Diagnostics may involve visually inspecting the components for scoring damage, such as by removing a spark plug and obtaining a bore scope to view inside the cylinder. In another approach, described by Yalin et al in US 2006/0037572, light from a cylinder spark event and/or combustion flame is used to diagnose for the presence of build-up and contaminants in the cylinder.
The inventors herein have recognized that the above discussed approaches can add extensive time, cost, and complexity to the diagnostics. The inventors have further recognized that in engine systems configured with laser ignition capabilities, components of the laser ignition system can be advantageously used to visually inspect the inside of the cylinder. In one example, the engine may be diagnosed by a method comprising: during non-combusting conditions, operating a laser ignition device, and indicating cylinder degradation based on a photodetector coupled to the cylinder. In this way, engine cylinder diagnostics can be expedited and simplified.
For example, during non-combusting conditions, the optics of the laser ignition system can be used to diagnose the cylinder. The lasers may be used to rapidly sweep the interior of each cylinder. In particular, low power light pulses may be emitted by the laser ignition device into the cylinder and detected by a photodetector system coupled to the head of the cylinder. The photodetector system may include a camera (such as a CCD camera) and a lens (such as a fish-eye lens), for detecting the light pulses. In one example, the light pulses may be emitted in the infra-red (IR) spectrum by the laser ignition device, and detected in the IR spectrum by the camera. Images of an interior of the cylinder (e.g., cylinder walls, cylinder intake and exhaust valves, etc.) may then be generated based on the detected pulses. The images may be transmitted (e.g., wirelessly) within the engine system and displayed to a service provider (e.g., mechanic) on a display of a vehicle center-console. The mechanic may then determine degradation of cylinder components based on the received images.
In some examples, during the non-combusting conditions, a knob of the center-console (e.g., a volume knob) may be used to actively control a position of the engine to assist in the visual inspection of the cylinder. For example, if a piston is positioned near a top of the cylinder, obstructing a full view of the cylinder, the mechanic may adjust the knob to move the engine position backwards or forwards to move the piston towards the bottom of the cylinder. As such, this may allow the mechanic to receive images representing a more complete view of the interior of the cylinder, and enable him to make a more precise inspection. A center-console knob may also be used to magnify the image of the cylinder on the display during the non-combusting conditions.
In this way, it may be possible to take advantage of a laser ignition system to reduce the time and cost associated with the visual inspection of an engine, without reducing the accuracy of the inspection. By correlating cylinder information gathered by an infra-red sensor following a laser operation during non-combusting conditions, diagnostic images of a cylinder interior can be generated. The diagnostic images can then be used to identify degradation of cylinder or valves of the engine. By using hardware already available in an engine configured with a laser ignition system, the need for costly, labor intensive, and time-consuming visual inspections can be reduced. Overall, engine inspection can be simplified without reducing inspection accuracy.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.